I am back on my blog after a wonderful holiday to Canada. I had a lot of fun staying in Vancouver and found BC to be a beautiful place.
Today's blog entry deals with quick but reliable estimate of the power consumption of vacuum pumps used in the chemical process industry. Some equations are presented below for the benefit of the readers:
Liquid Ring (NASH) pump:
BkW = 21.4*(SF)^{0.924}
Rotary Piston Pump:
BkW = 13.5*(SF)^{1.088}
where:
SF = 0.02-16 for "Liquid Ring (NASH) pump" and SF = 0.01-4 for "Rotary Piston Pump"
SF is defined as the "Size Factor" and can be calculated as follows:
SF = m / P; kg/ h/torr
where:
P = Operating pressure of system evacuated, torr (mmHga)
m = Air equivalent flow rate, kg/h
"m" can be calculated as follows:
m = G*sqroot((273.15+T)*28.96 / (293.15*MW))
where:
G = flow rate of the process gas being evacuated, kg/h
T = temperature of the process gas being evacuated, ⁰C
MW = molecular weight of the process gas being evacuated
The value of 293.15 in the equation indicates a reference temperature of 20 ⁰C for air equivalent flow which is recommended by the "Heat Exchange Institute" (HEI) for vacuum systems.
This concludes today's blog entry and I look forward to comments from the readers.
Regards,
Ankur.
Thanks Engr. Ankur